michael@0: /*
michael@0:  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
michael@0:  *
michael@0:  *  Use of this source code is governed by a BSD-style license
michael@0:  *  that can be found in the LICENSE file in the root of the source
michael@0:  *  tree. An additional intellectual property rights grant can be found
michael@0:  *  in the file PATENTS.  All contributing project authors may
michael@0:  *  be found in the AUTHORS file in the root of the source tree.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #include "vpx_scale/yv12config.h"
michael@0: #include "math.h"
michael@0: #include "vp8/common/systemdependent.h" /* for vp8_clear_system_state() */
michael@0: 
michael@0: #define MAX_PSNR 100
michael@0: 
michael@0: double vp8_mse2psnr(double Samples, double Peak, double Mse)
michael@0: {
michael@0:     double psnr;
michael@0: 
michael@0:     if ((double)Mse > 0.0)
michael@0:         psnr = 10.0 * log10(Peak * Peak * Samples / Mse);
michael@0:     else
michael@0:         psnr = MAX_PSNR;      /* Limit to prevent / 0 */
michael@0: 
michael@0:     if (psnr > MAX_PSNR)
michael@0:         psnr = MAX_PSNR;
michael@0: 
michael@0:     return psnr;
michael@0: }